An exogenic to endogenic thermal transition on Earth 3.9 billion years ago

Abstract On Earth, the primary driver of crustal magmatism is generally viewed as endogenic, a manifestation of loss of primordial and radiogenic heat from the interior. However, a much higher impact flux during the Hadean and earliest Archean eons would have significantly contributed to the crustal...

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Bibliographic Details
Main Authors: Christopher L. Kirkland, Janne Liebmann, Hamed Gamaleldien, Hugo K. H. Olierook, Maximilian Dröllner, Tim Johnson, Craig O’Neill, Axel K. Schmitt
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Communications Earth & Environment
Online Access:https://doi.org/10.1038/s43247-025-02575-9
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Summary:Abstract On Earth, the primary driver of crustal magmatism is generally viewed as endogenic, a manifestation of loss of primordial and radiogenic heat from the interior. However, a much higher impact flux during the Hadean and earliest Archean eons would have significantly contributed to the crustal heat budget on the early Earth. Here, we test this hypothesis using age, trace element, and oxygen isotope data from zircon grains from the Jack Hills, Western Australia, the oldest known terrestrial minerals. The chemical composition of the analyzed grains reveals a significant shift at around 3.9 billion years ago that is consistent with a transition from shallow to deeper melting, which we posit corresponds to the change from a thermal regime dominated by impacts to one dominated by heat loss from Earth’s interior. This change permitted continental crust to thicken, differentiate, and endure.
ISSN:2662-4435